330 research outputs found

    IDEAS-1997-2021-Final-Programs

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    This document records the final program for each of the 26 meetings of the International Database and Engineering Application Symposium from 1997 through 2021. These meetings were organized in various locations on three continents. Most of the papers published during these years are in the digital libraries of IEEE(1997-2007) or ACM(2008-2021)

    Distributed Spatial Data Sharing: a new era in sharing spatial data

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    The advancements in information and communications technology, including the widespread adoption of GPS-based sensors, improvements in computational data processing, and satellite imagery, have resulted in new data sources, stakeholders, and methods of producing, using, and sharing spatial data. Daily, vast amounts of data are produced by individuals interacting with digital content and through automated and semi-automated sensors deployed across the environment. A growing portion of this information contains geographic information directly or indirectly embedded within it. The widespread use of automated smart sensors and an increased variety of georeferenced media resulted in new individual data collectors. This raises a new set of social concerns around individual geopricacy and data ownership. These changes require new approaches to managing, sharing, and processing geographic data. With the appearance of distributed data-sharing technologies, some of these challenges may be addressed. This can be achieved by moving from centralized control and ownership of the data to a more distributed system. In such a system, the individuals are responsible for gathering and controlling access and storing data. Stepping into the new area of distributed spatial data sharing needs preparations, including developing tools and algorithms to work with spatial data in this new environment efficiently. Peer-to-peer (P2P) networks have become very popular for storing and sharing information in a decentralized approach. However, these networks lack the methods to process spatio-temporal queries. During the first chapter of this research, we propose a new spatio-temporal multi-level tree structure, Distributed Spatio-Temporal Tree (DSTree), which aims to address this problem. DSTree is capable of performing a range of spatio-temporal queries. We also propose a framework that uses blockchain to share a DSTree on the distributed network, and each user can replicate, query, or update it. Next, we proposed a dynamic k-anonymity algorithm to address geoprivacy concerns in distributed platforms. Individual dynamic control of geoprivacy is one of the primary purposes of the proposed framework introduced in this research. Sharing data within and between organizations can be enhanced by greater trust and transparency offered by distributed or decentralized technologies. Rather than depending on a central authority to manage geographic data, a decentralized framework would provide a fine-grained and transparent sharing capability. Users can also control the precision of shared spatial data with others. They are not limited to third-party algorithms to decide their privacy level and are also not limited to the binary levels of location sharing. As mentioned earlier, individuals and communities can benefit from distributed spatial data sharing. During the last chapter of this work, we develop an image-sharing platform, aka harvester safety application, for the Kakisa indigenous community in northern Canada. During this project, we investigate the potential of using a Distributed Spatial Data sharing (DSDS) infrastructure for small-scale data-sharing needs in indigenous communities. We explored the potential use case and challenges and proposed a DSDS architecture to allow users in small communities to share and query their data using DSDS. Looking at the current availability of distributed tools, the sustainable development of such applications needs accessible technology. We need easy-to-use tools to use distributed technologies on community-scale SDS. In conclusion, distributed technology is in its early stages and requires easy-to-use tools/methods and algorithms to handle, share and query geographic information. Once developed, it will be possible to contrast DSDS against other data systems and thereby evaluate the practical benefit of such systems. A distributed data-sharing platform needs a standard framework to share data between different entities. Just like the first decades of the appearance of the web, these tools need regulations and standards. Such can benefit individuals and small communities in the current chaotic spatial data-sharing environment controlled by the central bodies

    04441 Abstracts Collection -- Mobile Information Management

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    From 24.10.04 to 29.10.04, the Dagstuhl Seminar 04441 ``Mobile Information Management\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

    CHORUS Deliverable 2.1: State of the Art on Multimedia Search Engines

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    Based on the information provided by European projects and national initiatives related to multimedia search as well as domains experts that participated in the CHORUS Think-thanks and workshops, this document reports on the state of the art related to multimedia content search from, a technical, and socio-economic perspective. The technical perspective includes an up to date view on content based indexing and retrieval technologies, multimedia search in the context of mobile devices and peer-to-peer networks, and an overview of current evaluation and benchmark inititiatives to measure the performance of multimedia search engines. From a socio-economic perspective we inventorize the impact and legal consequences of these technical advances and point out future directions of research

    THREE TEMPORAL PERSPECTIVES ON DECENTRALIZED LOCATION-AWARE COMPUTING: PAST, PRESENT, FUTURE

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    Durant les quatre derniĂšres dĂ©cennies, la miniaturisation a permis la diffusion Ă  large Ă©chelle des ordinateurs, les rendant omniprĂ©sents. Aujourd’hui, le nombre d’objets connectĂ©s Ă  Internet ne cesse de croitre et cette tendance n’a pas l’air de ralentir. Ces objets, qui peuvent ĂȘtre des tĂ©lĂ©phones mobiles, des vĂ©hicules ou des senseurs, gĂ©nĂšrent de trĂšs grands volumes de donnĂ©es qui sont presque toujours associĂ©s Ă  un contexte spatiotemporel. Le volume de ces donnĂ©es est souvent si grand que leur traitement requiert la crĂ©ation de systĂšme distribuĂ©s qui impliquent la coopĂ©ration de plusieurs ordinateurs. La capacitĂ© de traiter ces donnĂ©es revĂȘt une importance sociĂ©tale. Par exemple: les donnĂ©es collectĂ©es lors de trajets en voiture permettent aujourd’hui d’éviter les em-bouteillages ou de partager son vĂ©hicule. Un autre exemple: dans un avenir proche, les donnĂ©es collectĂ©es Ă  l’aide de gyroscopes capables de dĂ©tecter les trous dans la chaussĂ©e permettront de mieux planifier les interventions de maintenance Ă  effectuer sur le rĂ©seau routier. Les domaines d’applications sont par consĂ©quent nombreux, de mĂȘme que les problĂšmes qui y sont associĂ©s. Les articles qui composent cette thĂšse traitent de systĂšmes qui partagent deux caractĂ©ristiques clĂ©s: un contexte spatiotemporel et une architecture dĂ©centralisĂ©e. De plus, les systĂšmes dĂ©crits dans ces articles s’articulent autours de trois axes temporels: le prĂ©sent, le passĂ©, et le futur. Les systĂšmes axĂ©s sur le prĂ©sent permettent Ă  un trĂšs grand nombre d’objets connectĂ©s de communiquer en fonction d’un contexte spatial avec des temps de rĂ©ponses proche du temps rĂ©el. Nos contributions dans ce domaine permettent Ă  ce type de systĂšme dĂ©centralisĂ© de s’adapter au volume de donnĂ©e Ă  traiter en s’étendant sur du matĂ©riel bon marchĂ©. Les systĂšmes axĂ©s sur le passĂ© ont pour but de faciliter l’accĂšs a de trĂšs grands volumes donnĂ©es spatiotemporelles collectĂ©es par des objets connectĂ©s. En d’autres termes, il s’agit d’indexer des trajectoires et d’exploiter ces indexes. Nos contributions dans ce domaine permettent de traiter des jeux de trajectoires particuliĂšrement denses, ce qui n’avait pas Ă©tĂ© fait auparavant. Enfin, les systĂšmes axĂ©s sur le futur utilisent les trajectoires passĂ©es pour prĂ©dire les trajectoires que des objets connectĂ©s suivront dans l’avenir. Nos contributions permettent de prĂ©dire les trajectoires suivies par des objets connectĂ©s avec une granularitĂ© jusque lĂ  inĂ©galĂ©e. Bien qu’impliquant des domaines diffĂ©rents, ces contributions s’articulent autour de dĂ©nominateurs communs des systĂšmes sous-jacents, ouvrant la possibilitĂ© de pouvoir traiter ces problĂšmes avec plus de gĂ©nĂ©ricitĂ© dans un avenir proche. -- During the past four decades, due to miniaturization computing devices have become ubiquitous and pervasive. Today, the number of objects connected to the Internet is in- creasing at a rapid pace and this trend does not seem to be slowing down. These objects, which can be smartphones, vehicles, or any kind of sensors, generate large amounts of data that are almost always associated with a spatio-temporal context. The amount of this data is often so large that their processing requires the creation of a distributed system, which involves the cooperation of several computers. The ability to process these data is important for society. For example: the data collected during car journeys already makes it possible to avoid traffic jams or to know about the need to organize a carpool. Another example: in the near future, the maintenance interventions to be carried out on the road network will be planned with data collected using gyroscopes that detect potholes. The application domains are therefore numerous, as are the prob- lems associated with them. The articles that make up this thesis deal with systems that share two key characteristics: a spatio-temporal context and a decentralized architec- ture. In addition, the systems described in these articles revolve around three temporal perspectives: the present, the past, and the future. Systems associated with the present perspective enable a very large number of connected objects to communicate in near real-time, according to a spatial context. Our contributions in this area enable this type of decentralized system to be scaled-out on commodity hardware, i.e., to adapt as the volume of data that arrives in the system increases. Systems associated with the past perspective, often referred to as trajectory indexes, are intended for the access to the large volume of spatio-temporal data collected by connected objects. Our contributions in this area makes it possible to handle particularly dense trajectory datasets, a problem that has not been addressed previously. Finally, systems associated with the future per- spective rely on past trajectories to predict the trajectories that the connected objects will follow. Our contributions predict the trajectories followed by connected objects with a previously unmet granularity. Although involving different domains, these con- tributions are structured around the common denominators of the underlying systems, which opens the possibility of being able to deal with these problems more generically in the near future

    Contextual Social Networking

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    The thesis centers around the multi-faceted research question of how contexts may be detected and derived that can be used for new context aware Social Networking services and for improving the usefulness of existing Social Networking services, giving rise to the notion of Contextual Social Networking. In a first foundational part, we characterize the closely related fields of Contextual-, Mobile-, and Decentralized Social Networking using different methods and focusing on different detailed aspects. A second part focuses on the question of how short-term and long-term social contexts as especially interesting forms of context for Social Networking may be derived. We focus on NLP based methods for the characterization of social relations as a typical form of long-term social contexts and on Mobile Social Signal Processing methods for deriving short-term social contexts on the basis of geometry of interaction and audio. We furthermore investigate, how personal social agents may combine such social context elements on various levels of abstraction. The third part discusses new and improved context aware Social Networking service concepts. We investigate special forms of awareness services, new forms of social information retrieval, social recommender systems, context aware privacy concepts and services and platforms supporting Open Innovation and creative processes. This version of the thesis does not contain the included publications because of copyrights of the journals etc. Contact in terms of the version with all included publications: Georg Groh, [email protected] zentrale Gegenstand der vorliegenden Arbeit ist die vielschichtige Frage, wie Kontexte detektiert und abgeleitet werden können, die dazu dienen können, neuartige kontextbewusste Social Networking Dienste zu schaffen und bestehende Dienste in ihrem Nutzwert zu verbessern. Die (noch nicht abgeschlossene) erfolgreiche Umsetzung dieses Programmes fĂŒhrt auf ein Konzept, das man als Contextual Social Networking bezeichnen kann. In einem grundlegenden ersten Teil werden die eng zusammenhĂ€ngenden Gebiete Contextual Social Networking, Mobile Social Networking und Decentralized Social Networking mit verschiedenen Methoden und unter Fokussierung auf verschiedene Detail-Aspekte nĂ€her beleuchtet und in Zusammenhang gesetzt. Ein zweiter Teil behandelt die Frage, wie soziale Kurzzeit- und Langzeit-Kontexte als fĂŒr das Social Networking besonders interessante Formen von Kontext gemessen und abgeleitet werden können. Ein Fokus liegt hierbei auf NLP Methoden zur Charakterisierung sozialer Beziehungen als einer typischen Form von sozialem Langzeit-Kontext. Ein weiterer Schwerpunkt liegt auf Methoden aus dem Mobile Social Signal Processing zur Ableitung sinnvoller sozialer Kurzzeit-Kontexte auf der Basis von Interaktionsgeometrien und Audio-Daten. Es wird ferner untersucht, wie persönliche soziale Agenten Kontext-Elemente verschiedener Abstraktionsgrade miteinander kombinieren können. Der dritte Teil behandelt neuartige und verbesserte Konzepte fĂŒr kontextbewusste Social Networking Dienste. Es werden spezielle Formen von Awareness Diensten, neue Formen von sozialem Information Retrieval, Konzepte fĂŒr kontextbewusstes Privacy Management und Dienste und Plattformen zur UnterstĂŒtzung von Open Innovation und KreativitĂ€t untersucht und vorgestellt. Diese Version der Habilitationsschrift enthĂ€lt die inkludierten Publikationen zurVermeidung von Copyright-Verletzungen auf Seiten der Journals u.a. nicht. Kontakt in Bezug auf die Version mit allen inkludierten Publikationen: Georg Groh, [email protected]

    DISTRIBUTED MULTIDIMENSIONAL INDEXING FOR SCIENTIFIC DATA ANALYSIS APPLICATIONS

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    Scientific data analysis applications require large scale computing power to effectively service client queries and also require large storage repositories for datasets that are generated continually from sensors and simulations. These scientific datasets are growing in size every day, and are becoming truly enormous. The goal of this dissertation is to provide efficient multidimensional indexing techniques that aid in navigating distributed scientific datasets. In this dissertation, we show significant improvements in accessing distributed large scientific datasets. The first approach we took to improve access to subsets of large multidimensional scientific datasets, was data chunking. The contents of scientific data files typically are a collection of multidimensional arrays, along with the corresponding metadata. Data chunking groups data elements into small chunks of a fixed, but data-specific, size to take advantage of spatio-temporal locality since it is not efficient to index individual data elements of large scientific datasets. The second approach was the design of an efficient multidimensional index for scientific datasets. This work investigates how existing multidimensional indexing structures perform on chunked scientific datasets, and compares their performance with that of our own indexing structure, SH-trees. Since R-trees were proposed, various multidimensional indexing structures have been proposed. However, there are a relatively small number of studies focused on improving the performance of indexing geographically distributed datasets, especially across heterogeneous machines. As a third approach, in an attempt to accelerate indexing performance for distributed datasets, we proposed several distributed multidimensional indexing schemes: replicated centralized indexing, hierarchical two level indexing, and decentralized two level indexing. Our experimental results show that great performance improvements are gained from distribution of multidimensional index. However, the design choices for distributed indexing, such as replication, partitioning, and decentralization, must be carefully considered since they may decrease the overall performance in certain situations. Therefore, this work provides performance guidelines to aid in selecting the best distributed multidimensional indexing scheme for various systems and applications. Finally, we describe how a distributed multidimensional indexing scheme can be used by a distributed multiple query optimization middleware as a case-study application to generate better query plans by leveraging information about the contents of remote caches

    Knowledge Discovery on the Grid

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    Computer-Driven Instructional Design with INTUITEL

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    INTUITEL is a research project that was co-financed by the European Commission with the aim to advance state-of-the-art e-learning systems via addition of guidance and feedback for learners. Through a combination of pedagogical knowledge, measured learning progress and a broad range of environmental and background data, INTUITEL systems will provide guidance towards an optimal learning pathway. This allows INTUITEL-enabled learning management systems to offer learners automated, personalised learning support so far only provided by human tutors INTUITEL is - in the first place - a design pattern for the creation of adaptive e-learning systems. It focuses on the reusability of existing learning material and especially the annotation with semantic meta data. INTUITEL introduces a novel approach that describes learning material as well as didactic and pedagogical meta knowledge by the use of ontologies. Learning recommendations are inferred from these ontologies during runtime. This way INTUITEL solves a common problem in the field of adaptive systems: it is not restricted to a certain field. Any content from any domain can be annotated. The INTUITEL research team also developed a prototype system. Both the theoretical foundations and how to implement your own INTUITEL system are discussed in this book
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